This invention relates generally to the field of mechanical fasteners for printed circuit board applications and, in particular, to a means and method for harnessing or retaining optical fiber to a printed circuit board or the like.
It is conventional to process or rout information to and from many types of electronic devices via fiber optic cables, especially when large amounts of data or large numbers of signals need to be transmitted. Typically, the electronic devices include printed circuit boards with various components used to process the signals or perform needed operations. The components may include typical electronic and opto-electronic devices such as transceivers and so on. Typically, one end of a fiber optic cable is fastened to the circuit board by a connector that allows communication with an incoming or external fiber optic cable. A length of fiber optic cable may then extend from the connector to a device attached to the circuit board and thus permit data transmission therebetween.
However, fiber optic cable has physical limitations, notably the bending it can withstand without failure. The limitation on the bending that a fiber optic cable can withstand prior to failure is known as the minimum bend radius. Due to this physical limitation, devices have been created to manage or harness fiber optic cable to a printed circuit board in such a manner as to prevent over bending of the fiber optic cable and to prevent entanglement of the cable with adjacent components or boards, especially during installation of the board. One such harnessing or retaining device is a retaining eye loop. This prior art device resembles a ring mounted upon a post. The post includes an arrow-shaped connector or head portion opposite the ring, which, when inserted through an opening in a circuit board, expands on the far side of the board and holds the retaining device in place. Examples of such snap leg latches are shown in FIGS. 1 and 2 of Des. Patent No. 278,143 (see also, U.S. Pat. Nos. 5,281,149, 5,255,159, and 6,058,579).
However, a disadvantage of such a retaining device is the difficulty of insertion of the connector portion, which can damage or break the circuit board. Further, the extent to which the retaining device extends outwardly from the circuit board, front and back, when installed, can increase the effective thickness of the circuit board, interfere with installation and damage adjacent components.
Accordingly, it would be desirable to provide an apparatus and method of providing improved retension of fiber optic cable to a circuit board, or the like, which overcomes the disadvantages described above.
One aspect of the present invention provides a clip apparatus for providing retension of fiber optic cable to a circuit board. The clip for retaining a length of fiber optic cable to a circuit board includes a body portion. The body portion of the apparatus includes at least a pair of spaced legs extending from the body portion, each of the legs is adapted to be received in a mounting opening formed in the PC board. Each of the spaced legs includes a foot portion adapted for securing the body to the circuit board and at least a pair of spaced arms extend from the body portion defining a slot between the arm and the body portion for receiving and retaining a portion of the length of fiber optic cable. The arms are spaced a distance from each other for retaining the fiber optic cable in an arc having a radius greater than a minimum bend radius of the fiber optic cable.
Another aspect of the invention provides a PC board and retaining clip assembly for retaining a length of fiber optic cable thereto, including a PC board including two pair of mounting openings. A pair of retaining clips are attached to the PC board. Each of the clips includes a body portion with a pair of spaced legs inserted into the pair of mounting openings. Each of the clips includes a pair of spaced arms. Each of the arms defines a slot with the body portion and a length of optic cable is retained in the slots of the pair of retaining clips.
Another aspect of the invention provides a method of operation of a retention clip adapted to be mounted directly to a PC board for retaining a length of fiber optic cable on the PC board, including providing a first and second pair of openings through the PC board in a spaced apart configuration. Pressure is applied to a first pair of legs on a first retention clip such that the first pair of legs may be inserted through the first pair of openings on the PC board. Pressure is released from the first pair of legs to retain the first clip to the PC board. Pressure is applied to a second pair of legs on a second retention clip such that the second pair of legs may be inserted through the second pair of openings on the PC board and retained thereto. Pressure is released from the second pair of legs to retain the second clip to the PC board and the length of fiber optic cable is secured to the first and second retention clips in a radius greater than a minimum bend radius of the fiber optic cable.
In yet another aspect of the method of the present invention the securing the length of fiber optic cable may include providing a first pair of slots to the first retention clip, providing a second pair of slots to the second retention clip, inserting a first portion of the length of the fiber optic cable into the first pair of slots, inserting a second portion of the length of the fiber optic cable into the second pair of slots and closing the first and second pair of slots.
Another aspect of the present invention provides a clip including a body portion. The body portion includes a pair of spaced first and second legs extending in a first direction from the body portion and a pair of spaced arms extending in a second direction from the body portion. The second direction is opposite from the first direction. The arms define a slot with the body portion. The arms may further include means for locking a distal end of each the arms to the body portion.